Adaptive robust control of 5 DOF Upper-limb exoskeleton robot

Abstract

This paper deals with the problem of robust output feedback control for a class of 5DOF upper-limb exoskeleton robot. It is able to assist with shoulder, elbow and wrist joint movements. Robustness is assured for the proposed controller in the presence of model uncertainties. Ultimate boundedness is proved for the presented adaptive observer-based controller. The other advantage of the proposed method is that the implemented information for feedback is only the measurement of position. The estimation of velocity and acceleration is provided by an adaptive observer without additional sensors. By utilizing a novel adaptive logic-based switching control scheme, a trajectory tracking performance is well achieved with a tunable error bound. The simulation example also verifies the effectiveness of the proposed control scheme.

Model-Free Adaptive Sliding Mode Robust Control with Neural Network Estimator for the Multi-Degree-of-Freedom Robotic Exoskeleton

“…e controller design is divided into three parts: first, to apply the model-free adaptive control theory to designing the controller; second, to enhance the robustness of the system and compensate the influence of unknown external disturbance, this paper combines the mode-free adaptive 2 Complexity control with both the sliding mode control and neural network estimator to compost the final controller; and finally, to prove that the convergence of the control error and the stability of the closed loop system with theoretical ways.…”

“…One therapist Exoskeleton robots in this paper are designed to be worn to provide rehabilitation therapy for the stroke patients [1][2][3][4]. e effective control strategies are so important for the exoskeleton to operate coordinately with the human upper limb.…”

“…In order to help the stroke patient, one therapist Exoskeleton robots were designed in this paper [1][2][3][4]; this robot is so complicated to be operated control to work with human upper limb, so the general control methods [5,6] are designed, and the other methods used the gravity and friction compensation controller also gained effective control performances [7][8][9]. Recently, researchers began to use more advanced control methods.…”

A Brief Review on Robotic Exoskeletons for Upper Extremity Rehabilitation to Find the Gap between Research Porotype and Commercial Type

“…In addition, misalignments between human and robot joint axes can also occur as a result of ignoring the motion of ICR in the exoskeleton robot [118]. There have been developed a plenty of exoskeletons that used a simple ball and socket joint in producing shoulder movement [56,87,101,102,106].…”

Bounded Control of an Actuated Lower-Limb Exoskeleton

“…This not only allows maintaining the bounded inputs of the control torque, but also provides an efficient convergence of the position and velocity of the physical system. In [28], an adaptive observer-based controller for an upper-limb exoskeleton robot is proposed and the boundedness is also proven.…”